Construction of rGO wrapping Cu2O/ZnO heterostructure photocatalyst for PNP and PAM degradation

Copper and zinc composite oxides (Cu 2 O/ZnO) were synthesized by an impregnation-reduction-air oxidation method. A series of Cu 2 O/ZnO/rGO ternary composites were prepared by coupling with graphene oxide (GO) with different mass fractions in a solvothermal reaction system. The microscopic morphology, crystal structure, and optical characteristics of the photocatalysts were characterized. The degradation of p-Nitrophenol (PNP) and polyacrylamide (PAM) by photocatalytic materials under simulated solar irradiation were studied, and the degradation kinetics were also investigated. The results showed that cubic Cu 2 O was modified by ZnO nanorods and distributed on rGO nanosheets. The ternary Cu 2 O/ZnO/rGO nanocomposites have stronger simulated solar absorption ability and higher photodegradation efficiency than pure ZnO and binary Cu 2 O/ZnO nanocomposites. When the amount of Cu 2 O/ZnO/rGO-10 was 0.3 g L −1 , the degradation rate of 10 mg L −1 PNP reached 98% at 90 min and 99.6% of 100 mg L −1 PAM at 30 min. The photocatalytic degradation processes of PNP and PAM all followed the pseudo-first-order kinetic model. Free radical trapping experiments showed that superoxide radicals were the main active substances to improve photocatalytic efficiency. In addition, after four recycles, the catalytic efficiency of Cu 2 O/ZnO/rGO-10 was still over 90%. It showed that Cu 2 O/ZnO/rGO-10 was a promising catalyst for wastewater treatment because of its good photostability and reusability.